Method for the manufacture of pile fabrics



Nov. 3, 1964 G. DE MESTRAL 3,154,837

METHOD FOR THE MANUFACTURE OF PILE FABRICS Original Filed May 9, 1958United States Patent 3,154,837 METHGD FGR THE MANUFACTURE GE FILEFABRECS George de lt iestral, .Nyon, Switzerland, assi aor toInternational Velcro Company, Estah, Nyon, Switzerland, a corporation ofLiechtenstein I Original application May 9, 1958, Ser. No. 734,347, newPatent No..3,009,235, dated Nov. 21, 1961. Divided and this applicationMar. 21, 1961, Ser. No. 195,846

1 Claim. (Cl. 2872) From Swiss Patent No. 295,638 and United StatesPatent No. 2,717,437, respectively, there is known a separable fasteningdevice comprising two elements, in that case, two layers of woven fabricof the velvet type in which the loops have been cut to form hooks. Thehooks .of these layers of fabric are formed by a thread of artificialmaterial, such as nylon or similar materials, so that they are capableof preserving their shape after cutting the loops to form books. Thepreservation of the shape of the hooks is obtained by a thermaltreatment appropriate for the particular artificial material used.

It will be understood that when two layers of this type are pressedintoface to face relation a substantial percentage of the hooks, engage withone another, and the two layers are ,thus hooked one to the other.Separation requires a forceof a considerable magnitude when it isattempted to release a large number of hooks at once but separation maybe quite readily eifected by progressively peeling the layers apart.Hooking or connecting devices of this character are adapted to be used,for example, as closing devices for clothing, blinds or the like, thusreplacing slide fasteners, buttons and other attachments of this type,particularly when a flexible closure, which is invisible and can beopened easily, is desirable.

It has been found that the use of one layer of fabric of the hookedvelvet type, as described above, with a layer of fabric of theloop-type, such as terry or uncut velvet, provides greatly improvedresistance to separation of the two layers of fabric.

Experience has shown that a hooked layer, of the type disclosed in saidPatent 2,717,437, provided, for example with 120 hooks per squarecentimeter has a relatively large portion of its surface which is notprovided with hooks. As a result, only about 30% of the total number ofhooks come into engagement with other hooks when two layers of suchhooked fabric are pressed to gether. In contrast with this, when onesuch layer with hooks is pressed against a layer having, for example,about 1000 loops per Square centimeter, the possibilities of hooking areconsiderably augmented.

The present application is a division of application Serial No. 734,347,filed May 9, 1958, for separable Fastening Device and Method andApparatus for the Manufacture of the Same, now US. Patent 3,009,235.

The present invention therefore has for its object the provision of amethod of manufacturing a separable fastener consisting of two elementsprovided with cooperating hooking members characterised in that one ofsaid elements is provided with hooks and the other with loops.

For the purpose of further enhancing the firmness of engagement of sucha separable fastener the present invention provides a method for weavingthe elements having the loops in which the loops are formed frommultifilarnent yarns having such a degree of twist that as an incidentof the formation of certain of the loops the filaments within such loopswill become untwisted and thus will fan out to form a large number ofindividual loops. This method afiords increased probability ofengagement of the hooks with the loops so that a ice I major percentage,if not all, of the hooks on the hookcarying element will become engagedwith a loop on the other element.

In the drawings; I l H FIG. 1 is an enlarged diagrammatic viewillustrating a portion of an apparatus and a method for the weaving ofeither hooked or looped fabrics suitable for the present invention; ,7 Ip 7 p FIG. 2 is a fragmentary plan View of a lancet with a series ofpile loops formed thereon in accordance with the present invention; 7 gV p 7 FIG. 3 is a diagrammatic, vertical sectional view of a fabric,taken in a plane parallel with the warps from which the loops are formedin accordance with the present invention; and p 7 g FIG. 4 is adiagrammatic, vertical sectional view taken in a plane perpendicular toFIG. 3 and showing the fabric of FIG, 3 in cooperative relationship witha hook element to form a fastening device. 7

With reference to FIG. 1, the terry or velvet-type uncut fabricillustrated is manufactured by forming a base fabric which comprises anumber of firmly woven weft threads 1 and warp threads 2. It will beunderstood that a large number of Warp threads 2 have been omitted andthat the weft threads 1 have been shown spread apart. The loops 3 ofsaid fabric are formed in supplementary warp threads passed over metalbars 5 in the formof lancets during the weaving operation, in a loom ofthe general type employed in weaving velvet ribbon. Said supplementarywarp threads 4 preferably are of artificial material, such as nylon orother material capable of being set by heat into a predetermined form.Such supplemental warps are thus capable of retainin by reason ofthermal heat treatment, the shape which has been imparted thereto duringweaving. Said supplementary warp threads 4 are multifilaments which arepreferred for the manufacture of the looped elements.

The fabric shown in FIG. 2 is a looped fabric woven as illustrated inFIGv 1 with lancets 5 all having substantially the same cross-section.Said fabric includes supplementary warp threads 4 of the multifilamenttype. By selecting multifilament threads or yarns 4 having an initialtwist or torsion equal to the amount of untwisting which will occur asthe yarns are carried in one direction across the lancets 5, every otherloop in the same series will be fanned out as shown at a while theremaining loops 7 will be even more tightly twisted as diagrammaticallyindicated in FIGS. 2 and 3. The untwisting just referred to results fromthe fact that the pile yarn 4 is secured against twisting about itslongitudinal axis at the point where it has been beaten into the basefabric 8 as it is formed from yarns 1 and 2 and at the point where thissame yarn 4 is held by tension in the doupe and against the reed dents.If, for example the pile yarn 4 is twisted clockwise (Z-twist) theportion thereof between the points just mentioned will untwist when thedoupe moves from the right (looking from the front of the loom) to theleft side of the lancet 5.

uch untwisting will constitute only a fraction of a com-. plete turn andthe initial twist of the yarn 4 is so selected as to be equal to theamount of untwisting which will occur in the particular length of yarnbetween such points of engagement. A similar fractional turn ofadditional twist will be added when the cloupe moves from left to right.

The separated filaments 6 in those loops which have been untwisted asjust described constitute individual loops, any one or more of which isreadily available for engagement with a hook 9 forming a part of a hookfastening element 19, as shown in FIG. 4. As noted above FIG. 4 is takenin a plane perpendicular to the plane of FIG; 3

a whereby a transversely extending row of untwisted loops 6 is shown.The hook fastening element 10 may be of any desired construction, forexample, it may be an element such as shown in the aforesaid U.S. PatentNo. 2,717,437.

In the weaving of the loop element herein disclosed it is preferred toweave the base fabric 8, formed from yarns 1 and 2 as shown in FIG. 1,very tightly and to weave the pile yarns 4 into the base fabric withconsiderable firmness. After the weaving operation the loops formed fromyarns 4 may be fixed or stabilized so that they retain their shape andposition. This fixing or stabilization may be effected by heat settingor by impregnation of the fabric, for example by adhesive products, orboth. In this manner a very large number of durable and firmly anchoredloops are provided.

A preferred manner of heat setting of the loops and fabric as justdescribed is to so arrange the loom on a which the fabric is woven thatthe lancets 5 extend in the direction of movement of the woven fabricfor a substantial distance whereby the loops may slide along the lancetsWhile continuing to surround the lancets. A heating device, not shown,may be arranged to heat the loops on the extended lancets 5 to a heatsetting temperature appropriate for the particular synthetic material ofwhich the loops and/or the fabric base 8 are formed. As indicated above,the base fabric 8 may be impregnated with an adhesive and preferably maybe impregnated or coated on thereverse face with a heat-settable resincapable of withstanding such temperatures as are likely to beencountered in normal usage of a fastener element.

The hooked fabric 1%) or the looped fabric 8 as shown in FIG. 4 may beproduced in various ways. For example, they may be Woven as relativelynarrow bands having a width required for the intended use. In that eventa number of such bands may be woven simultaneously on a loom of the typeused for Weaving ribbon. Alternatively,*they may be woven as a band ofconsiderable width which may be slit to form bands of desired width. Ineither event the bands may be of indeterminate length from which desiredlengths may be cut at will.

What is claimed is:

A method for the manufacture of a separable fastener member comprisingweaving a base fabric including warp and weft yarns and supplementalyarns forming a loop pile on said base fabric, utilizing as saidsupplemental yarns a multifilament synthetic resinous material having atwist in a predetermined direction, weaving each of said supplementalyarns in a predetermined zig-zag pattern such as substantially tountwist said supplemental yarn in every other loop formed consecutivelyfrom each of said supplementary yarns, whereby to separate the filamentsin each of such untwisted loops into discrete loops, and stabilizingsaid fabric to maintain said discrete loops in separated condition.

References Cited in the file of this patent UNITED STATES PATENTS1,672,712 Dulligan June 5, 1928 2,857,652 McNally et a1 Oct. 28, 19582,974,690 Park et a1 Mar. 14, 1961

